1. Field of the Invention
The invention relates to a device and process for interrupting an automobile engine ignition in the event of a stuck throttle.
2. Description of Related Art
Modern automobiles utilize either mechanical linkages or electromechanical devices to translate accelerator pedal movement into engine throttle. Both systems are subject to failure. Electromechanical systems may fail due to electromagnetic interference, improper processing, or the like. Mechanically linked systems may fail when the cable, rod, or other throttle linkage breaks.
For example, in electromechanical systems, automobiles utilize electronic switches and sensors to detect pedal displacement. These switches transmit signals to processor modules programmed to process the signals. Processor control modules utilize these processed signals to perform calculation and further control other sensors, motors, actuators, switches and the like to govern internal combustion engine operation and braking operations. When electronic or programmed devices malfunction, the engine can rev up or remain throttled unintentionally beyond the control of the driver. In such cases, brake operation may be diminished or insufficient to control the automobile unless deceleration occurs. Unless the malfunction stops, deceleration may not be possible unless the vehicle crashes. Similarly, electromagnetic interference is a growing concern in the use of electronic sensors used to control automobile engines. As manufacturers utilize an increasing number of electronic controls and device in automobiles, the amount of electromagnetic interference or EMI increases. Additionally, EMI may be introduced from sources external to the automobile itself. EMI can cause electronic device to behave erratically. Such erratic behavior could lead to processing units receiving incorrect information regarding the displacement on an accelerator pedal assembly, thereby causing an automobile to accelerate uncontrollably. Even if a driver removes their foot from the accelerator pedal, EMI may still operate to send improper signals to electrical sensors causing uncontrolled acceleration to continue. Additionally, a driver may not be able to stop if the engine throttle system is “stuck” at full throttle.
Vehicles having mechanical linkages utilize accelerator return springs and similar device to return the accelerator pedal to a predetermined position after the accelerator pedal is released. These vehicles use mechanical linkages such as throttle cables, rods, or other similar linkages to operate internal combustion engine throttle bodies. Malfunction in these mechanical linkages can cause an internal combustion engine to accelerate uncontrollably.
Both electromechanical and mechanical accelerator systems can also suffer from inadvertent “catching” of the accelerator pedal on floor mats and the like. When accelerator pedals become stuck in this manner, the accelerator can remain at full throttle even though the driver is no longer depressing the pedal.
Accordingly, what is needed is a device and method for interrupting the ignition of an automobile in the event of a mechanical linkage failure, EMI, or other unwanted operation causing acceleration when an accelerator pedal is no longer depressed by the operator.